This type of electric connector is suitably used for electric connectors in an airbag system. An airbag system comprises an airbag assembly mounted in a hidden compartment within a driver's cabin of a vehicle, and an electric type or electronic type control system. The control system is connected to the airbag assembly by means of a wire harness. Provided on the wire harness is an electric connector comprising a typical plug and a socket so as to allow an easy method for electric connection of an airbag assembly and a control system after these elements are separately mounted.
FIG. 13 is a view schematically and electrically showing a conventional, typical airbag system. In FIG. 13, a control system 100 is connected through lengths of electric wire 102 to a squib 101 being an ignition device that sends an electric current to a gas generator for development of an airbag in an airbag assembly (not shown). Such connection is achieved by an electric connector 103 that comprises a socket 104 and a plug 105. For example, U.S. Pat. No. 5,275,575 and Japanese Patent No. 2647336 disclose concrete examples of an electric connector applied on an airbag system.
Here, in an electric connector 103, a short-circuit insert 107 is mounted on a socket 104 to be able to short-circuit between a pair of lengths of electric wire connected to the squib 101. A ferrite bead 106 is arranged on the plug 105 while being fitted onto the lengths of electric wire 102 leading to contacts 108. The short-circuit insert 107 is provided as a safety device so as to prevent an airbag assembly from being actuated due to leaking static charge in manufacture and misconnection. The short-circuit insert is constructed to be able to switch between a short-circuit position and a non-short-circuit position. And, the ferrite bead 106 functions as a noise filter to prevent explosion by mistake in an airbag system built in a vehicle when a noise current flows through the squib 101 due to various electromagnetic waves from an outside such as lengths of electric wire, various electronic equipment, radio receiver, portable telephone, etc. in a vehicle.
The plug 105 is constructed with the contacts 108 and the ferrite bead 106 received in a housing 109 and a cap 110. In assembling the plug 105, the connection part is formed by fitting the ferrite bead 106 onto a pair of lengths of electric wire 102 after the contacts 108 and the lengths of electric wire 102 are connected in a L-shaped manner to each other. Next, the connection part comprising the contacts 108 and the ferrite bead 106 are received and positioned in the housing 109. Then, the housing 109 is covered by the cap 110 to form the plug 105.
However, positioning of both the contacts 108 and the ferrite bead 106 of the connection part in the housing 109 is performed at a time. At this time, positioning is performed while a distance from the contacts 108 to the ferrite bead 106 is maintained at a predetermined magnitude. Therefore, there is involved a problem that an operation of mounting the contacts 108 and the ferrite bead 106 as the connection part to the housing 109 becomes difficult.
The invention has been thought of in view of the above situation and has its object to provide a plug for electric connectors, of which an assembling operation can be simply and surely performed, and a method of assembling the same.